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src/hotspot/share/gc/shared/adaptiveSizePolicy.cpp
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rev 52689 : 8213224: Move code related to GC threads calculation out of AdaptiveSizePolicy
Summary: Consolidate code related to GC threads calculation into a single class
*** 1,7 ****
/*
! * Copyright (c) 2004, 2016, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
--- 1,7 ----
/*
! * Copyright (c) 2004, 2018, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*** 22,43 ****
*
*/
#include "precompiled.hpp"
#include "gc/shared/adaptiveSizePolicy.hpp"
- #include "gc/shared/collectorPolicy.hpp"
#include "gc/shared/gcCause.hpp"
#include "gc/shared/gcUtil.inline.hpp"
#include "gc/shared/softRefPolicy.hpp"
- #include "gc/shared/workgroup.hpp"
#include "logging/log.hpp"
#include "runtime/timer.hpp"
- #include "utilities/ostream.hpp"
elapsedTimer AdaptiveSizePolicy::_minor_timer;
elapsedTimer AdaptiveSizePolicy::_major_timer;
- bool AdaptiveSizePolicy::_debug_perturbation = false;
// The throughput goal is implemented as
// _throughput_goal = 1 - ( 1 / (1 + gc_cost_ratio))
// gc_cost_ratio is the ratio
// application cost / gc cost
--- 22,39 ----
*** 92,224 ****
_minor_timer.start();
_young_gen_policy_is_ready = false;
}
- // If the number of GC threads was set on the command line,
- // use it.
- // Else
- // Calculate the number of GC threads based on the number of Java threads.
- // Calculate the number of GC threads based on the size of the heap.
- // Use the larger.
-
- uint AdaptiveSizePolicy::calc_default_active_workers(uintx total_workers,
- const uintx min_workers,
- uintx active_workers,
- uintx application_workers) {
- // If the user has specifically set the number of
- // GC threads, use them.
-
- // If the user has turned off using a dynamic number of GC threads
- // or the users has requested a specific number, set the active
- // number of workers to all the workers.
-
- uintx new_active_workers = total_workers;
- uintx prev_active_workers = active_workers;
- uintx active_workers_by_JT = 0;
- uintx active_workers_by_heap_size = 0;
-
- // Always use at least min_workers but use up to
- // GCThreadsPerJavaThreads * application threads.
- active_workers_by_JT =
- MAX2((uintx) GCWorkersPerJavaThread * application_workers,
- min_workers);
-
- // Choose a number of GC threads based on the current size
- // of the heap. This may be complicated because the size of
- // the heap depends on factors such as the throughput goal.
- // Still a large heap should be collected by more GC threads.
- active_workers_by_heap_size =
- MAX2((size_t) 2U, Universe::heap()->capacity() / HeapSizePerGCThread);
-
- uintx max_active_workers =
- MAX2(active_workers_by_JT, active_workers_by_heap_size);
-
- new_active_workers = MIN2(max_active_workers, (uintx) total_workers);
-
- // Increase GC workers instantly but decrease them more
- // slowly.
- if (new_active_workers < prev_active_workers) {
- new_active_workers =
- MAX2(min_workers, (prev_active_workers + new_active_workers) / 2);
- }
-
- // Check once more that the number of workers is within the limits.
- assert(min_workers <= total_workers, "Minimum workers not consistent with total workers");
- assert(new_active_workers >= min_workers, "Minimum workers not observed");
- assert(new_active_workers <= total_workers, "Total workers not observed");
-
- if (ForceDynamicNumberOfGCThreads) {
- // Assume this is debugging and jiggle the number of GC threads.
- if (new_active_workers == prev_active_workers) {
- if (new_active_workers < total_workers) {
- new_active_workers++;
- } else if (new_active_workers > min_workers) {
- new_active_workers--;
- }
- }
- if (new_active_workers == total_workers) {
- if (_debug_perturbation) {
- new_active_workers = min_workers;
- }
- _debug_perturbation = !_debug_perturbation;
- }
- assert((new_active_workers <= ParallelGCThreads) &&
- (new_active_workers >= min_workers),
- "Jiggled active workers too much");
- }
-
- log_trace(gc, task)("GCTaskManager::calc_default_active_workers() : "
- "active_workers(): " UINTX_FORMAT " new_active_workers: " UINTX_FORMAT " "
- "prev_active_workers: " UINTX_FORMAT "\n"
- " active_workers_by_JT: " UINTX_FORMAT " active_workers_by_heap_size: " UINTX_FORMAT,
- active_workers, new_active_workers, prev_active_workers,
- active_workers_by_JT, active_workers_by_heap_size);
- assert(new_active_workers > 0, "Always need at least 1");
- return new_active_workers;
- }
-
- uint AdaptiveSizePolicy::calc_active_workers(uintx total_workers,
- uintx active_workers,
- uintx application_workers) {
- // If the user has specifically set the number of
- // GC threads, use them.
-
- // If the user has turned off using a dynamic number of GC threads
- // or the users has requested a specific number, set the active
- // number of workers to all the workers.
-
- uint new_active_workers;
- if (!UseDynamicNumberOfGCThreads ||
- (!FLAG_IS_DEFAULT(ParallelGCThreads) && !ForceDynamicNumberOfGCThreads)) {
- new_active_workers = total_workers;
- } else {
- uintx min_workers = (total_workers == 1) ? 1 : 2;
- new_active_workers = calc_default_active_workers(total_workers,
- min_workers,
- active_workers,
- application_workers);
- }
- assert(new_active_workers > 0, "Always need at least 1");
- return new_active_workers;
- }
-
- uint AdaptiveSizePolicy::calc_active_conc_workers(uintx total_workers,
- uintx active_workers,
- uintx application_workers) {
- if (!UseDynamicNumberOfGCThreads ||
- (!FLAG_IS_DEFAULT(ConcGCThreads) && !ForceDynamicNumberOfGCThreads)) {
- return ConcGCThreads;
- } else {
- uint no_of_gc_threads = calc_default_active_workers(total_workers,
- 1, /* Minimum number of workers */
- active_workers,
- application_workers);
- return no_of_gc_threads;
- }
- }
-
bool AdaptiveSizePolicy::tenuring_threshold_change() const {
return decrement_tenuring_threshold_for_gc_cost() ||
increment_tenuring_threshold_for_gc_cost() ||
decrement_tenuring_threshold_for_survivor_limit();
}
--- 88,97 ----
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